Namib Desert beetle

Onymacris unguicularis in the position for the collection of liquid

The fog drinkers Beetle ( Onymacris unguicularis ) is a beetle of the family of darkling beetles ( Tenebrionidae ). It is endemic to the Namib Desert.

Features

The fog drinkers beetle is black, about two inches tall and has striking long legs. The wing covers are like the pronotum almost entirely smooth and shiny, grooved only for back- end weak. The elytra are fused at the joint, the hind wings regressed. The space under the elytra is thereby converted to a respiratory chamber. The abdominal spiracles öffenen in this room, which only occurs on a column at the rear end with the outside world with information that can be closed. Depending on the outside temperature, it must renew its breath every 10 to 30 minutes. Since the dune sand is permeable to air, they have to not necessarily to the surface.

Way of life

Onymacris unguicularis is a type of open sand dunes. He lives in the loose shifting sand of the dune crests. At the approach of enemies, which is visually perceived, he dives quickly under the loose sand. The beetle is able not only to dig in the loose sand, but literally swim through it. The species is diurnal, but differs in the hottest time in the morning and evening hours from. Periods of rest he spends buried in the sand. For ingestion of the beetles preferred the sheltered, sunny side of the dunes. It feeds on the scanty been wafted here vegetable matter ( detritus ). Its larvae have the same diet, but they rarely come to the surface of the sand.

Desert tenebrionids the tribe Adesmiini are characteristic and rich in species for the desert areas of Namibia. Among the various types but have only two of the genus Onymacris ( unguicularis and bicolor) the ability to attract with its own body of surface water from the pulling from the Atlantic Ocean in the desert fog. These balance the animals on a dune with the head lowered down and stretch her ​​butt upwards at an angle of about 20 degrees to the wind, a headstand similar. The fog condenses into small droplets and the collected water can be used. This capability is essentially a behavior adjustment, no morphological specificity. As experiments have shown with dead animals, Onymacris unguicularis collects water not more efficient than related species without this behavior or tuft of grass. This way of life limited its range largely achieved by the fog, the western parts of the desert (see Distribution Map ). Rare is the style but also to about 45 km landward of dunes to be found.

Distribution of habitats

The various species of the genus Onymacris share different zones in the Namib:

• The fog drinkers Beetle Onymacris unguicularis inhabited the dune crests
• Onymacris rugatipennis lives in the flat terrain before Dünenfuß
• Onymacris laeviceps inhabited the vegetation at the Dünenfuß
• The White Desert beetle Onymacris plana inhabiting the Dünenfuß and is frequently encountered in Narasträuchern

Swell

• Hubert Roer (1986 ): Adjusts the black beetle Onymacris unguicularis ( Col., Tenebrionidae, Adesmiini ) to the fog zone of the Namib Desert. Bonn zoological Reviews 37 (2): 143-154.